Water, sewage and other liquids are often transported in subterranean pipelines. Typically, these pipelines consist of heavy sections of concrete pipe laid end-to-end in a trench. Other types of pipe, such as steel, cast iron, ductile iron, clay, plastic or fiberglass, can also be used. As can be appreciated, means must be provided for sealing the joints between adjacent pipe sections to prevent leaking of fluid, which may be harmful, into the ground and water table. Often this is accomplished by a double rubber gasket joint. The double rubber joint includes a sleeve with a cylindrical inner surface adapted to encircle recessed ends of the adjacent pipe sections. The sleeve also compresses rubber gaskets held in grooves about the outer circumference of each recessed pipe end to effectuate a tight seal.
For ease in storage and transportation of the pipe section prior to use in the field, the sleeve may be prepositioned on one end of each pipe section. Since the sliding of the sleeve over the pipe one end rolls the gasket, the gasket exerts a restoring force tending to urge the sleeve off the pipe. To counter this force, means must be provided to retain the sleeve on the pipe during the aforesaid storage and transportation and during the initial laying of the pipe section in a trench. Typically, with concrete pipe, cement mortar must be applied over the outer surface of the sleeve and the pipe ends, the mortar including an embedded wire mesh reinforcement. When cured, the reinforced mortar holds the sleeve on the pipe against the force of the rolled gasket.
Other means which have been used to hold the sleeve in place include adhesive bonding of the sleeve and pipe, pinning the sleeve to the pipe with radial dowels or bolts threaded through the sleeve to clamp it to the pipe.
Use of the exterior mortar and wire mesh or other means to retain the sleeve on the pipe has several disadvantages. The exterior mortar extends beyond the outer surface of the pipe requiring a wider, deeper, excavation of the trench proximate to the pipe ends. Accordingly, additional labor costs are involved to prepare the trench. Also, installation of the pipe section with a pipe sling may be more difficult due to the effect of the mortar upon the weight distribution. Another and more significant disadvantage where the joint diameter is larger than the outside of the pipe is that the pipe is prevented from being pushed through an excavation of a diameter equal to the outside of the pipe by a process called jacking. Furthermore, the joint is immobilized by the exterior mortar preventing movement needed to accommodate settlement of the pipe after installation. Settling of the immobilized pipeline may cause the pipe or its joints to crack and leak fluid. Factory application of the exterior mortar and wire mesh is expensive because of additional labor and material costs. Along these same lines, production is slowed while the mortar is allowed to cure. All in all, the overall manufacture of the pipe section is complicated. Accordingly, a need exists for a sleeve which is held onto a pipe end without requiring exterior mortar.